This invention is in the field of optical materials, and in particular is concerned with artificially created non-linear electro-optic materials which are suitable for use over a wide range of wavelengths from the visible well into the mm-wave regions. By definition, a non-linear material exhibits optical properties which depend upon the intensity of the input radiation. This typically means that the optical index of refraction, seen by an electro-magnetic wave propagating through the material, depends upon the magnitude of the electric field vector. This effect is sometimes described by the non-linear relationship between the induced optical polarization and the input electric field vector. The number of optical materials which exhibit a high degree of non-linearity is limited. In fact, in some regions of the spectrum, such as the 8-12 .mu.m region, optically active transparent materials are rare. Nonlinear optical materials may be used for an extensive array of applications. For example, they may be used to generate harmonics of an input field frequency. This is a very convenient method of generating a coherent spectral output in wavelength regions where laser lines are scarce. Such materials can also be used to generate sum and difference frequencies of two input lasers or to mix the output lines of three or more lasers. A major application of four-wave mixing, for example, is the generation of a phase-conjugate reflected signal to cancel the effects of beam distortion, whether caused within a laser cavity or by atmospheric or optical effects outside of the cavity. If the index of refraction increases with field intensity, the non-linear material self-focusses; if it decreases with intensity, it self-defocusses. Both of these effects can be used in conjunction with external optics to generate an optical bistability for high-speed, optically-driven switching. Unfortunately, most materials which are transparent to a given wavelength of radiation do not exhibit large non-linearities, and high field intensities are required to produce a usable effect. These intensities are typically of the same order of magnitude as the optical damage threshold of the materials, making for an inherent reliability problem. Moreover, there are no known bulk non-linear materials in the millimeter wave region. In view of the above, we set out to develop techniques, and ultimately media which possess artifically-generated non-linear optical properties. We call such media non-linear artificial dielectrics, and they are described herebelow.